Feasibility and sustainability of agroforestry in temperate industrialized agriculture: preliminary insights from California

Abstract

Intensive use of external inputs in specialized industrial farming systems has created significant socio-ecological externalities, including water and air pollution from nutrients and pesticides, soil erosion and depletion of carbon stocks, biodiversity loss and rising production costs. Ecological intensification is a strategy for reducing reliance on inputs by intentionally designing agroecosystems to harness biological processes and ecological relationships for the sustainable functioning of the system. Incorporating perennials and diversifying systems are two avenues for achieving ecological intensification, and both are characteristics of agroforestry. This preliminary report uses examples of agroforestry in the US state of California as a proof of concept to explore the agronomic and economic feasibility and sustainability benefits of agroforestry in intensive irrigated and temperate farming systems. An exploratory study of farmers experimenting with agroforestry systems and other agricultural professionals identified eight different variants of agroforestry systems being practiced on prime agricultural land in California, ranging from simple use of winter cover crops in orchards to multi-storied cropping systems with integrated grazing. Respondents noted benefits of reduced inputs and production costs, and better nutrient cycling, soil health and pest control. Trade-offs and challenges included increases in labor requirements and management complexity. Knowledge gaps included lack of guidance in biophysical systems design, lack of clarity about economic tradeoffs, and lack of information about ecosystem services benefits. In light of interviewees’ responses, we discuss the constraints and factors needed to foster the successful expansion of agroforestry systems in California and other regions characterized by industrialized farming.

On the complexity of agroforestry systems

“…In line with our results (Fig. 5.4), the lack of appropriately customised equipment has been put forward as a major challenge to scaling agroforestry in places as diverse as California in the USA (Brodt et al, 2019), Kenya (Nyberg et al, 2020) India (Upendranadh and Subbaiah, 2016) and Northern Europe (Graves et al, 2009).…”

“…It has been shown that for some agroforestry farmers keeping labour demand moderate is even more important than maximising productivity (Fujisawa et al, 2020;Scudder et al, 2022;Tilden et al, 2023) and in the future, labour availability is projected to be a major constraint for farmers (Ryan, 2023). It is often postulated that adopting more complex agroforestry systems increases labour demand (Brodt et al, 2019;Esche et al, 2022;Scudder et al, 2022;Smith et al, 2022), but labour inputs required to perform specific activities, such as weeding, might also decrease (Armengot et al, 2016). It is therefore relevant to assess the impact of agroforestry complexity on total labour demand, and also on specific labour activities.…”

“…F armers worldwide need to respond to land degradation and climate change by managing their soils to produce food while simultaneously increasing the provision of other ecosystem services (Schulte et al, 2015). A significant challenge to such multifunctional land management is the higher labour inputs that have been associated with management practices that increase the provision of ecosystems services (Brodt et al, 2019;, against a contextual backdrop of labour shortages in many rural communities around the world (Ryan, 2023).…”

Why Have China’s Poverty Eradication Policy Resulted in the Decline of Arable Land in Poverty-Stricken Areas?

“…Simultaneously, following the rehabilitation of degraded and desertified cropland, local governments promote adjustments to agricultural structures to reduce excessive land utilization. This may involve guiding farmers to diversify into other industries or altering crop planting patterns, such as promoting drought-resistant crops, crop rotation and fallow practices, and developing multi-story agroforestry [59]. These measures not only secure income for the impoverished population but also reduce the overexploitation of cropland, safeguarding the ecological environment from degradation and mitigating instances of unregulated cropland expansion due to livelihood constraints.…”

Agronomic cover crop management supports weed suppression and competition in California orchards

“…Cover crops offer flexible management options for diversifying agroecosystems and increasing the ecological function of orchard floors (Brodt et al 2019). As one cultural management practice within a suite of integrated pest management practices, cover crops can provide a framework for understanding the seasonality and phenology of weed life cycles while also promoting grower acceptance for some level of orchard vegetation (Linares et al 2008;Ramos et al 2010).…”